Malabsorption is a clinical term that encompasses defects occurring during the digestion and absorption of food nutrients by the gastrointestinal tract. The digestion or absorption of one or more types of nutrients (e.g., carbohydrates, fats, proteins) may be impaired in the digestion and/or transport across the intestinal mucosa into the systemic circulation. Malabsorption disorders encompass a number of different clinical entities that result in chronic diarrhea, abdominal distention, weight loss, dehydration, and/or failure to thrive. Clinical malabsorption can be broken down into several distinct conditions, both congenital and acquired, that affect one or more of the different steps in the intestinal hydrolysis and subsequent transport of nutrients.
While presenting symptoms, such as diarrhea and weight loss, may be common, the specific causes are usually established based on physiological evaluations. The treatment of the disease often depends on the establishment of a definitive etiology for the malabsorption. The osmotic load resulting from the inability of the intestine to absorb certain nutrient elements causes the presenting symptoms. Diarrhea is the most common symptomatic complaint. Additional symptoms include weight loss and fatigue, flatulence and abdominal distention, edema, anemia (e.g., microcytic (iron deficiency) or macrocytic (vitamin B-12 deficiency)).
Management of patients with malabsorption includes the correction of nutritional deficiencies and, when possible, the treatment of causative diseases (e.g., celiac disease, ulcerative colitis, small bowel syndrome). Nutritional support includes, for example, supplementing various minerals (e.g., calcium, magnesium, iron, and vitamins), caloric and protein replacement also is essential, use of medium-chain triglycerides as fat substitutes (e.g., they do not require micelle formation for absorption and their route of transport is portal rather than lymphatic), and parenteral nutrition.
Improved methods of preventing and/or treating malabsorption dysfunction and associated disorders (e.g., ulcerative colitis, short bowel syndrome, Crohn's disease) are needed.